mongo4cats
Mongo DB scala client wrapper compatible with Cats Effect ans Fs2. Available for Scala 2.12 and Scala 2.13.
Dependencies
Add this to your build.sbt (depends on cats-effect and FS2):
libraryDependencies += "io.github.kirill5k" %% "mongo4cats-core" % "0.1.3"
Quick Start Examples
Working with documents
import cats.effect.{ExitCode, IO, IOApp}
import mongo4cats.client.MongoClientF
import org.mongodb.scala.bson.Document
import org.mongodb.scala.model.{Filters, Sorts}
object Example extends IOApp {
override def run(args: List[String]): IO[ExitCode] =
MongoClientF.fromConnectionString[IO]("mongodb://localhost:27017").use { client =>
for {
db <- client.getDatabase("db")
coll <- db.getCollection("collection")
_ <- coll.insertMany[IO]((0 to 10).map(i => Document("name" -> s"doc-$i")).toList)
docs <- coll.find
.filter(Filters.regex("name", "doc-\\d+"))
.sort(Sorts.descending("name"))
.limit(5)
.all[IO]
_ <- IO(println(docs.toList))
} yield ExitCode.Success
}
}
Working with case classes
import cats.effect.{ExitCode, IO, IOApp}
import mongo4cats.client.MongoClientF
import org.mongodb.scala.bson.codecs.Macros._
import org.bson.codecs.configuration.CodecRegistries.{fromProviders, fromRegistries}
import org.mongodb.scala.MongoClient.DEFAULT_CODEC_REGISTRY
import org.mongodb.scala.bson.ObjectId
object Example extends IOApp {
final case class Person(_id: ObjectId, firstName: String, lastName: String)
val personCodecRegistry = fromRegistries(fromProviders(classOf[Person]), DEFAULT_CODEC_REGISTRY)
override def run(args: List[String]): IO[ExitCode] =
MongoClientF.fromConnectionString[IO]("mongodb://localhost:27017").use { client =>
for {
db <- client.getDatabase("db")
coll <- db.getCollection[Person]("collection", personCodecRegistry)
_ <- coll.insertOne[IO](Person(new ObjectId(), "John", "Bloggs"))
docs <- coll.find.stream[IO].compile.toList
_ <- IO(println(docs))
} yield ExitCode.Success
}
}
Refer to the official documentation for more sophisticated examples on working with case classes: https://mongodb.github.io/mongo-scala-driver/2.9/bson/macros/
